Russia's Inter RAO might build the world's largest coal-fired power plant to sell electricity to China in a sign of strengthening bilateral economic and political ties.

Chairman Boris Kovalchuk told reporters the Russian power monopoly would examine the cost and timetable required to build the 8-gigawatt plant, which would use coal from the Erkovetskaya deposit in the Amur region in Russia's Far East.

The announcement follows a historic $400 billion agreement to sell Russian natural gas to China for the next 30 years.